Water-back for stokers



H. J KERR.

WATER BACK FOR STOKERS. APPLICATION FILED DEC-8,1917- 1,390,791. PatentedSept. 13,1921,

'I I I VEN TOR REF 5 W 3/ BY m fl -a UNITED STATES PATENT OFFICE.

EDWARD J. KERR, OF IBAYONNE, NEW JERSEY, AS SIGNOR TO THE BABCOCKec WILCOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

WATER-BACK FOR s'roxnas.

Specification of Letters Patent. Patented Sept. 13, 1921.

Application filed December 8, 1917. Serial No. 206,145.

To all whom it may concern:

I3e it known that I, HowARn J. KERR, a cltlzen of the United States, residing at Bayonne, in the county of Hudson and State of New Jersey, have invented. certain new and useful Improvements in Water-Backs for Stokers, of which the following is a specification.

My invention relates to a steam boiler furnace and more particularly to an arrange ment of Water boxes at the rear of a chain grate stoker, and will be understood by reference to the accompanying drawings in which Figure 1 is a vertical longitudinal section through a portion of the furnace; Fig. 2 is a vertical section on the plane of the line 2-2 of Fig. 1 showing the boxes arranged in series; Fig. 3 a vertical section showing the boxes arranged in parallel; Fig.

1 4 a transverse sectionon an enlarged scale through the water boxes, and Fig. 5 is a view similar to Fig. 4 showing three boxes arranged one above the other. Similar refer ence numerals indicate similar parts in the several views.

In the drawings the numeral 1 designates a chain grate stoker of any approved type, and 2 a bridge wall overhanging the rear of the stoker. In the space. between the stoker and the overhang of the wall are two water boxes 3 and 4, both circular in section and the former set higher than, and slightly in advance of, the latter. These boxes extend from side to side of the furnace, as shown in Figs. 2 and 3, and have connections leading to the boiler circulation. In Fig. 2 the boxes are connected in series. The pipe 5, which may lead from the mud drum of the boiler, is connected to the lower box 4, the boxes bein connected through a manifold 6 and nipp es 7. The outlet pipe 8 from the upper box may be connected to a steam and water drum of a Stirling boiler, or the uptake headers of a Babcock & Wilcox boiler. In this arrangement the water is caused to flow through the boxes in opposite directions, as indicated by the arrows.

In Fi 3 the boxes are connected in parallel, havmg independent water inlet connections 9 and 10, and independent outlet connections 11 and 12, respectively. In this arrangement the boxes have a slight inclination upward in the direction of the flow of the water throu h them. The amount of this inclination oes not usually affect the function of the water box in acting on the fuel bed, with the stoker placed level, to an extent that interferes with securing the best results. If desired, the stoker can be correspondingly inclined thus providing a space of even width between the face of the stoker grate which supports the fuel bed and the water box. In both arrangements the inlet connections to the boxes are protected from, and the outlet connections are exposed to, the heat of the furnace, the first feature being important to prevent burning of the inlet connections and the latter feature increasing the rapidity of the circulation.

Any steam formed in the boxes of a water back will prevent contact of the water with the top of the box and exposing the top of the box to a high enough temperaturewill result in overheating and springing or dis tortingthe box. To prevent this it is neces sary to protect the tops of the boxes. In the present arrangement the upper box 3 is protected by the tiling of the bridge wall 2 which rests upon it, and the lower box is protected by the upper box, the latter being set in advance of the lower box and in such position as to prevent exposure of the top of the lower box to the radiant heat. By employing two boxes I eliminate trouble due to the accumulation of slag and clinker which has been found to exist when a single box is used.

The lower box is so placed above the rear.

of the stoker-that it serves to retard the bed of fire and to plane or crush down the ash and clinker by gradually reducing its thickness, as the ash and clinker travel beneath it.

Any space between the boxes 3 and 4 may be sealed by a triangular piece of tile or fire brick 13, or a mass of plastic material which will be solidfied by the heat, or the boxes may be set closely together and no seal used.

If desired, three or more boxes may be set one above the other in accordance with the method described and shown, and in I have illustrated three such drums, 1nd1- cated by the reference characters 3, 4 and 4.

What I claim and desire to secure by Letters Patent of the United States is 2-- 1. A steam boiler furnace comprising a stoker, a bridge wall, and a plurality of water boxes set above the rear of the stoker, each upper box being placed above and in advance of the one immediately beneath it,

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the lower part of the upper box being below the top of the next one beneath and the distance between theboxes being such that the upper box protects the top of the lower box from the radiant heat of the fire bed.

2. A steam boiler furnace comprising a Stoker, ,a bridge wall, and a plurality of water boxes set above the rear of the stoker, each box other than the lowermost being placed above and ,in advance of the one immediately beneath, the lower part of the upper 'b'oxbeing belowsthe top of the next one beneath and thedistance between the boxes being such that the upper box protects thetop of the lower box from the radiant heat of the fire bed, said'boxes being connected withthe boiler circulation.

3. Asteam boiler furnace comprising a Stoker, a bridge wall, a plurality of water boxes set above the rear of the Stoker, each upper box being placed above and in ad- Vance of theone immediately beneath it, the

lower part of the upper box belng below the top of the next one beneath and the distance between the boxes being such that the upper box protects the top of the lower box from the radiant heat of the fire bed, and independent connections for said boxes with the boiler circulation.

4. Asteam boiler furnace comprising a st-oker, a bridge wall, a plurality of water boxes placed above the rear of the stoker and spaced apart, each upper box being above and in advance of the one immediately beneathv it, therlower part of the upper box being belowthetop of the next one beneath, and a refractory closure between the boxes.

5, A steam boiler furnace comprising a Stoker, abridge wall extending over the rear of the stoker, a plurality of water boxes in the space between the stoker and the overhanger the bridge wall, said boxes being circular in section and spaced apart and eaclrupper box set above and in advance of the one immediately beneath it, the lower part of the upper box being below the top of thenext one beneath and the distance between the boxes being such that the upper boxjprotect'sthe top of the lower box from tnaradiant heat of the fire bed, and con means for said boxes with the boiler circu l ation. v e A g Astana, bo ler furnace comprlsi'ng a Stoker, a bridge" wall, and two transverse water boxes set above the rear of the stoker. the upper box being in advance of the lower box and in front of the central, vertical. longitudinal plane of the lower box and the distance between the boxes being such that the upper box protects the top of the lower box from the radiant heat of the fire bed.

7. A steam boiler furnace comprising a stoker, a bridge wall, and a plurality of water boxes circular in cross section set above the rear of the stoker, each upper box being placed above and in advance of the one immediately beneath it, the lower part of the upper box being below the top of the next one beneath and the distance between the boxes being such that the upper box protects the top of the lower box from the radiant heat of the fire bed.

8. A steam boiler furnace comprising a stoker, a bridge wall, a plurality of water boxes circular in cross section set above the rear of the Stoker, each upper box being placed above and 111 advance of the one namediately beneath it, the lower part of the upper box being below the top of the next one beneath, and a refractory closure between the boxes.

9. A steam boiler furnace comprising a stoker, a bridge wall, a plurality of water boxes placed above the rear of the stoker and spaced apart, each upper box being above and in advance of the one immediately beneath it, the lower part of the upper box being below the top of the next one beneath, and a refractory closure placed back of said boxes and seated by gravity therebetween.

10. A steam boiler furnace comprising a stok'er, a bridge wall, a plurality of water boxes placed above the rear of the stokcr and spaced apart, each upper box being above and in advance of the one immediately beneath it, the lower part of the upper box being below the top of the next one beneath, and a refractory closure placed back of said boxes and seated by gravity therebetween, and forming contact with the lower box in advance of the top thereof.

In testimony whereof, I have hereunto signed my name in the presence of two subscribing witnesses.

HOVARD J. KER-R. \Vi't'n'esses F. J. VvnnLnn, C RY, 

